Re: [Xen-devel] [PATCH 17/38] arm: allow p2m to be created with specific MATTR.

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Fri, 1 Jun 2012, Ian Campbell wrote:
> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> ---
>  xen/arch/arm/p2m.c         |   15 ++++++++-------
>  xen/include/asm-arm/page.h |    6 ++++--
>  2 files changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
> index 9b40e93..46c6f17 100644
> --- a/xen/arch/arm/p2m.c
> +++ b/xen/arch/arm/p2m.c
> @@ -148,7 +148,7 @@ static int p2m_create_entry(struct domain *d,
>      clear_page(p);
>      unmap_domain_page(p);
>  
> -    pte = mfn_to_p2m_entry(page_to_mfn(page));
> +    pte = mfn_to_p2m_entry(page_to_mfn(page), MATTR_MEM);
>  
>      write_pte(entry, pte);
>  

This works because p2m_create_entry is always called to create first or
second level entries only.
Maybe we should rename p2m_create_entry to p2m_create_table_entry for
clarity? Or add a comment?


> @@ -159,7 +159,8 @@ static int create_p2m_entries(struct domain *d,
>                       int alloc,
>                       paddr_t start_gpaddr,
>                       paddr_t end_gpaddr,
> -                     paddr_t maddr)
> +                     paddr_t maddr,
> +                     int mattr)
>  {
>      int rc;
>      struct p2m_domain *p2m = &d->arch.p2m;
> @@ -235,11 +236,11 @@ static int create_p2m_entries(struct domain *d,
>                  goto out;
>              }
>  
> -            pte = mfn_to_p2m_entry(page_to_mfn(page));
> +            pte = mfn_to_p2m_entry(page_to_mfn(page), mattr);
>  
>              write_pte(&third[third_table_offset(addr)], pte);
>          } else {
> -            lpae_t pte = mfn_to_p2m_entry(maddr >> PAGE_SHIFT);
> +            lpae_t pte = mfn_to_p2m_entry(maddr >> PAGE_SHIFT, mattr);
>              write_pte(&third[third_table_offset(addr)], pte);
>              maddr += PAGE_SIZE;
>          }
> @@ -263,7 +264,7 @@ int p2m_populate_ram(struct domain *d,
>                       paddr_t start,
>                       paddr_t end)
>  {
> -    return create_p2m_entries(d, 1, start, end, 0);
> +    return create_p2m_entries(d, 1, start, end, 0, MATTR_MEM);
>  }
>  
>  int map_mmio_regions(struct domain *d,
> @@ -271,7 +272,7 @@ int map_mmio_regions(struct domain *d,
>                       paddr_t end_gaddr,
>                       paddr_t maddr)
>  {
> -    return create_p2m_entries(d, 0, start_gaddr, end_gaddr, maddr);
> +    return create_p2m_entries(d, 0, start_gaddr, end_gaddr, maddr, 
> MATTR_DEV);
>  }
>  
>  int guest_physmap_add_page(struct domain *d,
> @@ -281,7 +282,7 @@ int guest_physmap_add_page(struct domain *d,
>  {
>      return create_p2m_entries(d, 0, gpfn << PAGE_SHIFT,
>                                (gpfn + (1<<page_order)) << PAGE_SHIFT,
> -                              mfn << PAGE_SHIFT);
> +                              mfn << PAGE_SHIFT, MATTR_MEM);
>  }
>  
>  void guest_physmap_remove_page(struct domain *d,
> diff --git a/xen/include/asm-arm/page.h b/xen/include/asm-arm/page.h
> index c7b6530..bb1729a 100644
> --- a/xen/include/asm-arm/page.h
> +++ b/xen/include/asm-arm/page.h
> @@ -46,6 +46,8 @@
>  #define DEV_WC        BUFFERABLE
>  #define DEV_CACHED    WRITEBACK
>  
> +#define MATTR_DEV     0x1
> +#define MATTR_MEM     0xf
>  
>  #ifndef __ASSEMBLY__
>  
> @@ -169,7 +171,7 @@ static inline lpae_t mfn_to_xen_entry(unsigned long mfn)
>      return e;
>  }
>  
> -static inline lpae_t mfn_to_p2m_entry(unsigned long mfn)
> +static inline lpae_t mfn_to_p2m_entry(unsigned long mfn, unsigned int mattr)
>  {
>      paddr_t pa = ((paddr_t) mfn) << PAGE_SHIFT;
>      lpae_t e = (lpae_t) {
> @@ -178,7 +180,7 @@ static inline lpae_t mfn_to_p2m_entry(unsigned long mfn)
>          .p2m.sh = LPAE_SH_OUTER,
>          .p2m.write = 1,
>          .p2m.read = 1,
> -        .p2m.mattr = 0xf,
> +        .p2m.mattr = mattr,
>          .p2m.table = 1,
>          .p2m.valid = 1,
>      };

the rest of the patch is fine

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